This invention relates to facsimile transmitters and receivers of the type utilized to transmit and receive information-bearing signals representing the dark-light variations on a document located at the transmitter and converting the information-bearing signals to marks or images on a copy medium located at a receiver so as to form a copy which is a reasonable facsimile of the original document.
Most facsimile transmitters and receivers in commercial use at the present time are supplied with document or copy medium sheets by hand. In other words, an operator takes an individual sheet of paper, whether the individual document or a blank piece of copy medium, and places that sheet on or in the scanning means of the transmitter or receiver, typically a drum having a clamp for clamping one edge of the sheet.
In some commercially available facsimile equipment, cassettes or magazines are utilized to store a plurality of sheets prior to feeding to the scanning means. These cassettes include separating members which are inserted between adjacent pairs of sheets so as to assure that each sheet will, with reliability, be fed to the scanning means and more particularly, fed to the clamp associated with a drum.
Where sheet feeding is at all automated, it is important to assure that the sheet will be appropriately fed to a position of necessary alignment with the scanning means. Where the scanning means includes a rotatable drum with a clamp, automated sheet feeding necessarily requires a good deal of registration or alignment between the sheet and the drum so as to assure proper clamping.
Where automated feeding is utilized, certain delays may be encountered in feeding sheets. This delay may result in part from the time required to transport a sheet from a storage area to the scanning means. Where an operator performs the storage by inserting a sheet into an automated transport path, the operator himself may contribute to the delay. In facsimile operations, any such delay may be extremely costly since a telephone associated with facsimile equipment may be off hook and telephone time is being consumed.
In systems involving automated sheet transport, it may be necessary to provide a plurality of sheet feeding means. Such a plurality may complicate sheet alignment with the scanning means. Not only do the plurality of feed means provide ample opportunity for misalignment, a plurality of feed means may also make it difficult to provide for any alignment corrections in the transport path because of simultaneous engagement of two or more feed means with a single sheet.